sendmsg.cpp

#include <iostream>
#include <string>

using namespace std;

#ifdef _WIN32
    #include <windows.h>

    void _sleep(unsigned int milliseconds)
    {
        Sleep(milliseconds);
    }
#else
    #include <unistd.h>

    void _sleep(unsigned int milliseconds)
    {
        usleep(milliseconds * 1000);
    }
#endif

bool sendMsg(const string&, const string&);
bool sendMsgErr(const string&, const string&);
bool sendMsg(const string&, const string&, int, unsigned int);
bool sendMsgRecursion(const string&, const string&, int);
bool sendMsgRecursionErr(const string&, const string&, int);
bool sendMsgRecursion(const string&, const string&, int, unsigned int);

const unsigned int ERROR_TIMES = 3;
unsigned int call_count = 0;

int main(int argc, char *argv[])
{
    string server = "127.0.0.1";
    string data = "test pass";
    
    cout << "connecting to " << server << " ..." << endl;
    bool result = sendMsgRecursion(server, data, 3, 1000);
    
    if (result) {
        cout << "result: success" << endl;
    } else {
        cout << "result: failure" << endl;
    }
    
    return 0;
}

bool sendMsg(const string& server, const string& data, int retry_times, unsigned int retry_interval_milliseconds)
{
    bool flag = false;
    if (retry_times <= 0) return flag;
    
    for (; retry_times > 0; retry_times--) {
        try {
            flag = sendMsgErr(server, data);
            if (flag) break;
        } catch (...) {
            cout << "retry: " << retry_times << endl;
            _sleep(retry_interval_milliseconds);
        }
    }
    
    return flag;
}

bool sendMsg(const string& server, const string& data)
{
    bool flag = false;
    cout << server << endl;
    cout << data << endl;
    
    flag = true;
    
    return flag;
}

bool sendMsgErr(const string& server, const string& data)
{
    call_count++;
    if (call_count <= ERROR_TIMES) {
        throw "err_code";
    } else {
        return sendMsg(server, data);
    }
}

bool sendMsgRecursion(const string& server, const string& data, int retry_times, unsigned int retry_interval_milliseconds)
{
    if (retry_times <= 0) return false;
    
    try {
        return sendMsgRecursionErr(server, data, retry_times--);
    } catch (...) {
        cout << "retry: " << retry_times+1 << endl;
        _sleep(retry_interval_milliseconds);
        return sendMsgRecursion(server, data, retry_times--, retry_interval_milliseconds);
    }
    
}

bool sendMsgRecursion(const string& server, const string& data, int retry_times)
{
    bool flag = false;
    cout << server << endl;
    cout << data << endl;
    
    flag = true;
    
    return flag;
}

bool sendMsgRecursionErr(const string& server, const string& data, int retry_times)
{
    call_count++;
    if (call_count <= ERROR_TIMES) {
        throw "err_code";
    } else {
        return sendMsgRecursion(server, data, retry_times);
    }
}